1. Field of the Invention
The invention relates to a wood planing machine, more particularly to a wood planing machine with improvement relating to a thickness adjustment device.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional wood planing machine is shown to include an elongated machine base 10, left and right pairs of posts 13, vertical left and right threaded rods 16, a cutter carriage 12, a cutter unit (not visible), a carriage locking mechanism, and a thickness adjustment device.
As illustrated, the machine base 10 has a top surface, opposed left and right mounting sides 101 spaced apart from each other in a longitudinal direction, and opposed feed-in and take-out sides disposed apart from each other in a transverse direction.
The left and right pairs of posts 13 are fixed on the top surface of the machine base 10 at the left and right mounting sides 101, respectively.
The cutter carriage 12 is disposed above the machine base 10, and has opposite end portions mounted respectively, vertically and movably on the left and right pairs of posts 13.
The left and right threaded rods 16 (only the latter is visible in FIG. 2) are mounted respectively and rotatably on the left and right mounting sides 101 of the machine base 10 such that the threaded rods 16 are disposed respectively between the left and right pairs of posts 13, and extend threadedly through the end portions of the cutter carriage 12 for moving the cutter carriage 12 along the posts 13 when the threaded rods 16 rotate on the machine base 10, thereby adjusting height of the cutter carriage 12.
The cutter unit (not visible) is disposed on the cutter carriage 12 in a known manner for cutting a workpiece 100 fed therebelow in the transverse direction.
The carriage locking mechanism locks the cutter carriage 12 at a selected height.
The thickness adjustment device includes a rotary disc 14 rotatably mounted on the machine base 10 at the right mounting side 101, and formed with three vertical stems 141 of different lengths, and a horizontal shaft-holding arm 150 fixed on the right end portion of the cutter carriage 12, and a vertical stop shaft 15 fastened threadedly to the shaft-holding arm 150 on the cutter carriage 12 in such a manner that rotation of the rotary disc 14 can result in alignment of a selected one of the vertical stems 141 with the stop shaft 15, thereby determining a thickness to be removed from the workpiece 100 by the cutter unit 12.
However, the aforesaid conventional wood planing machine provides restricted thickness adjustment since there are only three vertical stems 141 on the rotary disc 14, thereby adversely affecting the adjustment range.